Rotating eliminator



8 Sheets-Sheet 1 S R o T N E v k F s J. F. KING, JR., ET AL ROTATINGELIMINATOR Nov. 1, 1966 Filed March 12, 1964 1966 J. F. KING, JR, ET AL3,282,032

ROTATING ELIMINATOR Filed March 12, 1964 8 Sheets-Sheet 2 INVENTOR 5James F. King Jr. Agnew HBwhnson Jr U /MW IJMZW 19 Pm ATTORNEY S Nov. 1,1966 J. F KING, JR, ET AL 3,282,032

ROTATI NG ELIMINATOR 8 Sheets-Sheet 5 Filed March 12, 1964 James F K/ngJ Agnew H. BaJwnson J 1 Pwpw ATTORNEY s N V- 1966 J. F. KING, JR, ET AL3,282,032

ROTATING ELIMINATOR 8 Sheets-Sheet 4 m J m 0 H M m JJ. R W rm m m mvwm BWM W N 06% H m 5i. i S r Lm #H 8 Q .1 4 6 Q 0 J BY 9 AW Filed March 12,1964 Nov. 1, 1966 Filed March 12, 1964 J. F. KING, JR., ET AL ROTATINGELIMINA'I'OR 8 Sheets-Sheet 5 FINVENTORS J Kl J A3323; H. Ba lQnsonJr YNov. 1, 1966 J. F. KING, JR., ET AL 3,282,032

ROTATING ELIMINATOR Filed March 12, 1964 8 Sheets-Sheet e ulnlm INVENTORJames F KI 1% Agnew H. Bah son Jr BY JZM JJJ Qge-NKQ 1 jW/PA/EV Nov. 1,1966 J. F. KING, JR, ET AL 3,282,032

ROTATING ELIMINATOR 8 Sheets-Sheet 7 Filed March 12, 1964 INVENTORSJames F King Jr- Aghew H. Ba l'lson Jr BY Nov. 1, 1956 J KlNG, JR, ET AL3,282,032

ROTATING ELIMINATOR Filed March 1.2, 1964 8 Sheets-Sheet 8 INVENTORSJames Fkmg Jr. Agnew H.5cwhn5on Jr. BY

United States Patent 3,282,032 ROTATHN ELHMINATOR This invention, whichis a continuation-in-part of our copending application Serial No.264,473 filed March 5, 1963, now abandoned, which in turn was acontinuationin-part of our prior application Serial No. 169,432, filedJanuary 29, 1962, and now abandoned, relates to apparatus for treatingair for use in air conditioning and air washing systems wherein, forexample, the air stream is brought into direct contact with a waterspray which serves the dual purpose of washing and removing foreignparticles from the air and adding moisture to the air before deliveringthe same to a particular point of use. In order to remove any waterdroplets that may become entrained with the air during the washingaction, it is customary to interpose an eliminator in the air streamafter leaving the washer. These eliminators have, in general, been ofthe stationary type comprising an assembly of plates with surfaces setat an angle to the direction of air flow through the same so that theairstream is compelled to follow a tortuous path thus separating out theheavier droplets of water as the airstream repeatedly changes itsdirection of flow through the plate. These stationary eliminators whichare known generally as broken plate eliminators have two principaldisadvantages, one of which is the comparatively high static pressureloss involved in driving the air through the tortuous paths of theeliminator. Another disadvantage of this type of eliminator is that itbecomes clogged within a very short time when used in conjunction withconditioning of air in a textile mill wherein, in addition to dirt, theair contains a large amount of lint liberated during the textileprocessing operation. This lint becomes entrained in the air which istaken back to the air washer, and a considerable portion of the lintpasses through the washer section into the eliminator section where itbecomes lodged between the plates. In order to keep the eliminator evenreasonably clean, the mill is therefore required to establish a periodiccleaning schedule for the eliminators and they must also carefullyscreen out the linty material from the return air and, in some cases,from fresh air taken in from the outside.

As an improvement over the stationary types of eliminators others haveproposed use of eliminators of the rotary type which include a rotatingblade asembly, the blades of which are, for example, V-shaped so as torequire the air to undergo a change in direction as it passes throughthe blade assembly. One such construction is disclosed in US. Patent No.2,932,360, granted April 12, 1960, in the name of Ernest C. Hungate.

The present invention also relates to an eliminator of the rotating typebut is considered to be an improvement over prior developed rotaryeliminators in that it operates with a considerably lower pressure lossas compared with the high internal static pressure which characterizesthe prior designs.

In general, the rotor element of the eliminator is composed of anassembly of blades which are essentially planar throughout their areaand extend outwardly from a rotatable hub to which they are secured. Theblades can be located in planes parallel to the axis of rotation of thehub or they can be located in planes at an acute angle to the rotationalaxis. Air entering channels formed between adjacent straight blades ofthe improved rotating eliminator will be caused to move in a helicalpath as it travels ice from one end of the eliminator to the other. Thepitch of the helical path taken by the air will be determined by thevelocity of the air and by the rotational speed of the eliminator. Forexample, these two factors combined with a total length through theeliminator may be such that each increment of air entering a channelbetween adjacent blades of the eliminator will be rotate-d through anangle 60 before exiting. Thus, the rotary displacement of the channelcauses any water particle entrained with the air to move by virtue ofits own inertia toward the trailing blade of the eliminator. During thetime the water laden air is enclosed within the blades of theeliminator, it is being rotated at reasonably high speed and eachparticle of matter having a mass is propelled by centrifugal forcetoward the outside of the eliminator. In ad dition to this centrifugalseparation of water from the air, there also exists a collateralscrubbing action between the blades which helps to film the water out.upon the surface of the eliminator blades so that it can come up torotational speed quickly.

The improved rotating eliminator may be positively driven by anysuitable means such as an electric motor, or it may be auto-rotated byincorporating a windmill within the housing containing the rotaryeliminator, the windmill being located at the air exit end of theeliminator. Moreover, the eliminator assembly may be rotated at a fixedspeed or at a variable speed controlled by humidity conditions in a roomwhere the air is to be supplied after leaving the eliminator so as toelfect an accurate control over the amount of moisture removed by theblade action and centrifugal force and thereby obtain a completelycontrollable wet duct system. On the other hand, the eliminator can berotated at a speed sufficient to effect removal of all liquid to supplya dry duct system with entrainment free air.

In accordance with another aspect of the invention, the eliminator maybe composed of a plurality of eliminator assemblies arranged in cascadealong the longitudinal axis of the eliminator. All of the cascadedeliminator assemblies may be mounted for rotation, or the cascadedarrangement may include a stationary eliminator assembly between twoadjacent rotating eliminator assemblies to re-direct the air streambetween adjacent eliminator assemblies and bring about the mostefifective air entrance angle into the downstream eliminator assemblyfor the purpose of eliminating the entrained water particles. The bladesof adjacent eliminator assemblies may also be located in planes at anacute angle to the axis of rotation and in such case the angularlylocated blades of one eliminator assembly may be located at an angle tothe angularly located blades of an adjacent eliminator assembly.Adjacent eliminator assemblies may be rotated in opposite directions togain some of the advantages inherent in an eliminator of the brokenplate type but without entailing any appreciable static losses.Moreover, the various eliminator assemblies may be rotated atprogressively increasing speeds in the direction of air flow through theeliminator, so that the slower rotating assemblies at the air inlet andwhich are burdened with the removal of heavier water droplets, dirt andlint will run without excessive vibration, and the faster rotatingassemblies nearer the air exit end of the eliminator will create greatercentrifugal forces on the air and any water the eliminator. Adjacenteliminator assemblies may be rotated in opposite directions and atvarying speeds to gain the advantages before mentioned. Adjacenteliminator sections may also be rotated in the same direction and atdifferent speeds. A particular advantageous mode of operation of a groupof three cascaded sections is one wherein all three sections rotate inthe same direction but wherein the center section rotates at a slowerspeed than two outer sections which latter rotate at the same speed. Forexample, the two outer sections can rotate at a speed of 130 r.p.m.while the center section rotates at a speed of 34 r.p.m. In addition,each eliminator section may have a different number of blades;preferably the section with the fewest blades upstream of the eliminatorand the sections with more blades downstream. Used in this manner, theupstream sections which received the maximum amount of entrained waterand dirt which is being washed from the air have less total surface areato contaminate and are more easily cleaned when cleaning becomesnecessary and the downstream sections with more blades which are runningin a much cleaner atmosphere are capable of removing the smaller waterparticles from the air. This latter function is possible sinceeliminating efliciency is, in part, improved when more blades are addedto the hub or when the eliminator blades are revolved at a higherrotational speed.

In accordance with another aspect of the invention, arrangements may bemade for cleaning off the surfaces of the blades of the eliminatorassemblies. This may be accomplished by means of flooding nozzlespositioned within the barrel or casing within which the eliminatorassemblies are located, the nozzles being located at the end of theeliminator assembly in one or more rows extending from the periphery ofthe blades to the hub on which they are mounted and serving to directstreams of water longitudinally of the assembly between the blades so asto clean off any particles of dirt, lint, etc., which may have becomelodged in the gaps between adjacent blades, and also clean off thesurfaces of the blades themselves. The flooding nozzles may also bepositioned so as to discharge clean-off water in a generally radialdirection onto the blade surfaces from the outer periphery inward towardthe hub. The barrel or casing which encloses the eliminator assembly orassemblies if there be more than one can also be conveniently providedwith a door extending for the length of the barrel so as to facilitateinspection and cleaning.

While the blades of the improved rotating eliminator assembly are madeplanar throughout substantially the entire working surface areasthereof, the radially outer surface portions of the blades may beroughened such as by the inclusion of ribs or bumps or the like in orderto assist in breaking up the surface tension of the liquid being removedfrom the air stream so that minute water droplets have a better tendencyto coagulate and thereby be more readily acted upon by centrifugal forcewhich is particularly high at the radially outer surface portions of theblades.

The foregoing as well as other objects and advantages inherent in theinvention will become more clearly understood from the followingdetailed description of various embodiments thereof and from theaccompanying drawings wherein:

FIG. 1 is a view mostly in central longitudinal section through acomplete air washer incorporating the improved rotary eliminatorstructure and with some parts shown in elevation;

FIG. 2 is a partial vertical section of the rotor structure of theeliminator showing the manner in which the radially inner ends of theplanar blades are anchored;

FIG. 3 is a view in perspective of the radially inner edge portion ofone of the planar eliminator blades showing the piano hinge constructionby which the blades are secured in place;

FIG. 4 is a side elevation of a radially inner portion of one of theeliminator blades;

FIG. 5 is an end view of FIG. 4;

FIG. 6 is also a partial vertical section of the rotor structure showingthe particular details by which the rotor blades are anchored to a hubplate;

FIG. 7 is a vertical section taken on line 77 of FIG. 6;

FIG. 8 is also a partial vertical section of the radially outer portionsof the blades showing the manner in which the blades are held in spacedrelation;

FIG. 9 is a vertical section taken on line 9-9 of FIG.

FIG. 10 is a view in perspective showing the details of construction ofthe spacer element used in spacing the router portions of the bladesfrom one another;

FIG. 11 is a central longitudinal sectional view throughthe eliminatorsection of an air washer illustrating a modified construction featuringa plurality of rotatable eliminator assemblies arranged in cascade alongthe axis of air flow and wherein provision is made for independentrotation of the assemblies;

FIG. 12 is a view 'in development of a portion of the periphery of amodified construction for the eliminator blades wherein the air inletand air outlet ends of the rotatable blade assembly are curved inopposite directions respectively so as to facilitate the fiow of airinto and out of the channels between the blades;

FIG. 13 is a view of an eliminator blade modified to include a surfaceroughened by ribs for facilitating removal of moisture from the blades;

FIG. 14 is a View of a portion of an assembly of blades in accordancewith the construction of FIG. 13.

FIG. 15 is a view of a modified embodiment wherein rotation of theeliminator assembly is effected by means of an adjustable pitch windmillmounted on the shaft which carries the eliminator assembly;

FIG.16 is a section view taken on line 1616 of FIG. 15;

FIG. 17 is a central longitudinal sectional view similar to FIG. 11 butshowing a modification which includes means for reverse fiooding of theblade surfaces and the spaces between adjacent blades to wash off anydirt or lint which may have become stuck on the blade surfaces or jammedinto the gaps between adjacent blades;

FIG. 18 is a somewhat diagrammatic view showing the embodiment whereinthe blades are arranged in planes parallel to the axis of rotation ofthe bladed eliminator assembly; and

FIG. 19 is a view similar to FIG. 18 illustrating an embodiment whereinthe blades are arranged in planes which lie at an acute angle to theaxis of rotation of the bladed eliminator assembly.

With reference now to the drawings and to FIG. 1 in particular, theimproved high-velocity, low static pressure air washer and eliminatorassembly is seen to include an elongated casing 10 through which the airis passed for washing and for thereafter eliminating all or a desiredportion of the water droplets which become entrained in the air streamafter leaving the washer section of the assembly. The casing 10 thusincludes a cylindrical entrance chamber 11 seen at the extreme left inFIG. 1 in which a fan 12 is located, the function of the fan being toforce the incoming dirt and lint laden air to be treated through thewasher chamber 13 and thereafter through the eliminator chamber 14. Atruncated conical section 10b of the casing which diverges in thedirection of air flow therethrough is connected to the cylindricalentrance section 10a, and conical section 10b is followed by acylindrical section 100, the casing sections 1% and 10c serving toestablish the washer chamber 13. The cylindrical casing part has arectangular opening cut into the under portion thereof and a sump 15 iswelded to the wall of this opening. A drain pipe 16 is welded to anopening in the bottom wall of this sump so that it can drain away thewater which is fed to the washer and which is not evaporated. This drainwater is preferably used on a recirculating basis in the washer so thatpipe 16 is a gravity drain back to a filter unit 17 to remove foreignparticles washed away from the air stream so that the clean water canthen be directed from the filter through a pump 18 which returns thewater via a pipe 19 to a water inlet header which is constituted by anelongated tube Zll that extends centrally and generally horizontallywithin the casing sections ltlb, title. The water header tube is closedat the opposite ends thereof by Walls 22 and 23. The diameter of thewater header tube 21 at the end wall 22 adjacent fan 12 is preferablythe same as the hub portion 12a of the fan blades so that tube 21 notonly functions as a header but also serves as an air directing means forthe air stream which flows through the washer chamber 13. Water headertube 21 which is pressurized by the water admitted to the same from pump18 is provided with a plurality of outlet nozzles 24, eight of which areseen in FIG. 1, which are secured directly into the wall of the headertube 21 so that their spray pattern is directed outwardly toward theconical wall section ltib. The number of nozzles can be selected asnecessary to establish the required water fiow for the washer and theyare preferably located in a helical path around the periphery of thewater header so that their spray patterns overlap. In addition, eachfull circle of nozzles is preferably spaced so that no two nozzles liealong the central axis of header tube 21 but there is a symmetry betweenthe rows of nozzles to achieve a more complete coverage of the area ofthe Washer which is near the center line.

In addition to the nozzles 24, other nozzles 25 which can be in anyappropriate number for the size of the washer, are elevated on headerpipes 26' which extend radially outward from header tube 21 to theapproximate center line between the transition wall part b and head ertube 21. These nozzles 25 are directed downstream of the air flow tohelp fill in any gaps which possibly may have been left by the nozzles24. This 90 overlapping of the water issuing from the individual nozzlesassures complete coverage of the washing space within the washer chamberl3'and provides an optimum condition for ob taining a higher saturationefficiency for the unit.

Water header 21 is maintained in its proper position inside of thewasher chamber 13 by four struts in the form of plates 27 located 90apart at the entrance to the conical transition section Nb and by asimilar arrangement of four plate-like struts 28 placed at the junctionbetween the washer section 13 and eliminator section 14. These latterstruts also serve to support the front bearing 29 for the front end ofthe rotating eliminator. assembly 3%) which will be described later infurther detail.

Washer chamber MD is provided with another water supply header 20 whichconnects with a separate and continuous water supply located outside thewasher casing. This header 26) is mounted rigidly to the lower support23 to maintain a spaced parallel relation to the tapered front surfaceof the blades 37 of the eliminator assembly 30, and is provided with aplurality of nozzles 2% which are so positioned as to directhigh-velocity low-volume jets of water substantially parallel to theupstream face of the eliminator assembly. Although the nozzles Zita arelocated on only one header and spray preferably downwardly toward thesump 1'5, each eliminator blade 37 will have its upstream edge scrubbedby the water jets issuing from nozzles Ztla as the blades 37individually rotate past the water jets. The scrubbing action of theWater jets from nozzles 20a is preferably included on an air washer ofthe type described if long fiber material such as cotton is being washedfrom the air flowing through the washer because some of the fibers drapeacross the edge of the blade, half of their length on one blade side andthe other half on the blade opposite side in such a manner as to not beeasily removable.

Air Washer saturation efliciency is determined partially by how muchwater is added to the air stream as it moves through a chamber such aschamber in, and control of such a washer is generally accomplished bythrottling the sprays from the primary nozzles such as plates 33 and 34respectively.

the nozzles 24, 25. This action reduces the water flushing action oneliminator blades 37 but does not diminish the lint being drawn throughthe washer to contaminate the eliminator. As a result, the continuousjet sprays from nozzles 2dr: are necessary to remove the lint which isdeposited in the eliminator. The more usual procedure is to supplyhigh-volume, low-pressure water from many nozzles facing directly intothe eliminator and these are normally termed flooding nozzles. However,it has been found that this procedure allows the saturation efficiencyof the washer to drop only to approximately 50% even though the primarynozzles have been closed off. The improved arrangement which has beendescribed featuring the set of nozzles a allows the washer saturation tofall to approximately 20% since a very carefully directed high-pressure,low-volume Water cleaning spray is used.

Since there are no air straightener vanes behind the blades of the fan12 and the air will be leading at a vector angle relative to thevelocity of the air through the washer and the rotational speed of thefan, struts 27 are preferably slanted relative to the longitudinal axisof the washer chamber 13 so that they will not interfere with thisdischarge helix angle since the air swirl tends to centrifuge the washerwater out towards the walls 10b, 100 of the Washer chamber and therebyeliminate much of the water which could possibly have to be eliminatedin the straight bladed, rotating eliminator assembly 30. The otherstruts 28 could also be slanted in the same manner as struts 27 butsince the former are so close to the rotating eliminator assembly 39 andbecause of some practical difficulty in slanting these larger platemembers, they are installed parallel with the longitudinal axis of theWasher.

The rotating eliminator assembly 30 is mounted for rotation on shaft 31which is supported near each end by ball bearing assemblies 29, 32 whichare bolted to Plates 33 and 34 are welded respectively onto the struts28 for the front bearing assembly and struts 35 for the 'rear bearingassembly which are similar in number and position to the struts 23. Thetwo sets of eliminator bearing support struts 2S and 35 are secured toreinforced wall portions of the overall casing structure 10.

An annular air seal baffle plate 36 is secured between the connectingflanges of the washer and eliminator wall sections 10c, 10d of thecasing and the inner edge of this baffle extends to the periphery of theblades 37 of the rotating eliminator assembly 30 to prevent highvelocity air from traveling through the annular space defined by thewall ltld of the eliminator section and the outer edges of theeliminator blades 37.

The longitudinal axis of the bly 3th is offset slightly upward of theeliminator section lid of the apparatus so that there is a larger spaceunderneath the rotating eliminator assembly than above it, this spacebeing used to contain water in such quantity that the slight pressurehead developed will force the water back through a scupper 38 and backinto sump 15 from whence it can drain through pipe 16.

The air exit end of the rotating eliminator assembly 31 is surrounded bya seal assembly of solid sheet metal which consists of a tnuncatedconical section 39 rigidly attached to the blades 37 of the eliminatorassembly. A reversely extending truncated conical section 41 is rigidlyattached to section 39 and extends rearward away from the eliminator. Anannular shaped baffle plate 42 extending radially is secured to thetruncated section 41. The truncated conical sections 39, 41 and theannular baffle plate 42 constitute the rotating components-of the airseal at this end of the eliminator assembly. The stationary parts of theseal are comprised of an annular baffle plate 43 extending radiallyoutward from a cylindrical Wall section 44 which extends axially of theelimirotating eliminator assemfrom the longitudinal axis nator assembly30 and lies inwardly of the truncated section 41. The cylindricalsection 44 is fitted into a circular opening in the end wall plate 45 ofcasing 16 for the rotating eliminator assembly. A truncated conicalbaffle 40 is rigidly attached to this end plate 45 and extends into thearea lying between the rotating conical section 41 and bafile plate 42.The drive shaft 31 of the rotating eliminator assembly terminates in agear motor 46 which is mounted directly on the shaft. This gear motorhas a torque arm 47 attached to the motor case and secured to one of therear struts 35 so that it can effect rotation of shaft 31.

The rotating eliminator is comprised of an assembly of the radiallyextending planar blades 37 arranged in planes parallel with the axis ofrotation and which rotates with the motor driven shaft 31. This is alsoillustrated diagrammatically in FIG. 18. In the illustrated embodimentthe radially inner edge portions of the blades 37 are cut and bentoutward from the plane of the plate in opposite directions as shown inFIGS. 27 to form a series of axially spaced loops 48 or piano hingeparts at each side of the blade. The hinge parts 48 of adjacent bladesare interlinked and held together by means of rods 49 which pass throughthe hinge parts 48 and are made slightly longer than the length of theeliminator blades so as to project from each end thereof. The oppositeend portions of the rods 49 are passed through apertures in end plates51 which are secured fast to hubs 52 which are fitted onto shaft 31 andsecured thereto such as by keying 50 or other suitable means. To keepthe rods 49 from moving axially, annular rings 53 are removably securedto the plates 51 such as by bolts 54 and these rings include axiallyoffset port-ions 53a which abut against the ends of the rods. Thus, inorder to dismantle the eliminator blade assembly it is only necessary toremove the annular rings 53, thus exposing the ends of the rods 49 whichcan then be removed by grasping the ends and withdrawing them axiallyfrom the hinge portions 48 of the blades.

In order to substantially form a sealed cylindrical surface extendingcircumferentially under all of the eliminator blades 37 to prevent theflow of water laden air into and through the practically hollow hubportion of the rotating eliminator assembly 30, it will be seen fromFIG. 2 that the interfitting laterally turned radially inner edgeportions 48 of adjacent blades 37 also serve to close the separationbetween adjacent planar surf-aces of the blades in addition to theirfunction as hinge parts.

Preferably, the radially outer portions of the eliminator blades 37 areheld in spaced relation by means of rubber spacers 55. Each of thesespacers as shown in FIGS. 810, there being one spacer for eacheliminator blade, includes a cylindrical body portion 55a which makes apress fit within an opening 37a through the eliminator blade 37, atapered socket 551; on one end and a tapered plug 550 on the oppositeend of the same size as the socket. As shown in FIG. 8, the plug end 55cof one spacer unit is fitted into the socket end 55b on the spacer unitin the adjacent eliminator blade,

When motor 46 is energized thus causing shaft 31 and hence also theassembly of eliminator blades 37 to rotate, air washed in the washerchamber 13 and any water droplets entrained therein entering thechannels formed between adjacent blades 37 will be caused to move in ahelical path as it travels from one end of the eliminator blade assemblyto the other. As explained, the pitch of the helical path taken by theair will be determined by the velocity of the air and by the rotationalspeed of the eliminator blade assembly. During the time the water ladenair is enclosed within the blades of the eliminator it is being rotatedat a reasonably high speed and each particle of water and otherparticles having mass are propelled by centrifugal force toward theouter edges of the eliminator blades. In addition to this centrifugalseparationof the water from the air there also exists a collateralscrubbing action betwen the blades 37 which helps to film the water '8out upon the surfaces of these blades so that it can come up torotational speed more quickly. Water removed from the air by therotating eliminator assembly is collected in the lower portion of thecasing section 10d and is returned to the sump 16 for recirculation inthe water header 21 after being passed through the filter 17 and pump18.

In accordance with the invention, the eliminator blades 37 must beplanar throughout substantially their entire working area in order toproduce the desired centrifugally induced helically outward flow path ofthe water droplets separated out of the air stream. However, ifcompletely planar blades as shown in the embodiment of FIGS. 1-10 areused and which are set at zero angle to the rotational axis, i.e. theylie in planes parallel with such axis, the air relative direction intothe blades is at some definite angle to the blades dependent upon thevelocity of the air and the air will tend to buffet at the blade ends.To avoid this, the end portions of the blades at the air entrance end tothe eliminator may be given a slight twist in one direction and the endportions of the blades at the air exit end of the eliminator given aslight twist in the opposite direction. Such a modified bladeconstruction is depicted in FIG. 12, the blades 56 being shown withoppositely directed twisted end portions 56a and 56b. These twistedportions thus match the entrance and exit directions of the air so thatthe air will enter and leave the eliminator more smoothly and will passthrough the casing beyond the eliminator with virtually no swirl.

If desired, surface portions of the blades may be lightly embossed orroughened such as by bumps or ribs, in order to assure a more completeremoval of water droplets from the air. This roughening of the bladesurfaces serves to establish a discontinuous surface which is ofassistance in breaking up the surface tension of the liquid beingremoved from the air stream so that minute water droplets have a bettertendency to coagulate and thereby be more readily acted upon by thecentrifugal force which is particularly high at the radially outerportions of the blades. The slight roughening of the blade surfaces maybe effected throughout the area of the blade or it may be limited tocertain areas. Roughening nearer the axis of rotation is of lessadvantage since in these areas the centrifugal force factor is less asis also the water volume.

FIGS. 13 and 14 show one suitable form of roughening for the surfaceportions of the blades 37 by the provision of a series of spaced ribs 57which may be rectilinear or preferably, as shown, having a curvilinearconfiguration approximating the helical flow path of the water beingcentrifuged from the eliminator. The ribs 57 whether rectilinear orcurved, are slanted generally in the direction of water flow through theeliminator, as shown. The ribbed portions of the blades may be limitedto the air exit end of the blades, or as shown, they may be appliedthroughout the length of the blades.

In the embodiment of the invention illustrated in FIGS. 1-10, theeliminator section consists of a single rotating bladed assembly. Ifdesired, a plurality of such bladed rotating assemblies may be cascadedalong the rotational axis and driven independently so that adjacentassemblies can be rotated in the same or in opposite directions, and atthe same or at different speeds. One advantage of rotating adjacentassemblies in opposite directions is that it varies the resulting vectorof the peripheral speed of the blades relative to the axial velocity ofthe air flow through the apparatus. Thus, it approaches the action of aso-called broken plate eliminator but does not have the high static headcharacteristic of the latter.

The rotating eliminator assemblies nearer the air entrance end theretocan be driven at a comparatively low speed so as to remove most of theinitial trash which otherwise would contribute to undesirable dynamicunbalance in the rotating assembly. The subsequently followingeliminator assemblies can be driven at higher speeds since most of thetrash will have been removed and hence, these are more clearlydynamically balanced 69 and will rotate satisfactorily at higher speedswithout danger of excessive vibration. Thus, the rotational speed ofeach eliminator assembly can be virtually proportional to the weight ofwater or lint which the assembly must handle at its position in thecascaded group of assemblies.

FIG. 11 illustrates one practical embodiment for arranging a pluralityof rotary eliminator assemblies in cascade along the axis of rotation.In this view, only the eliminator section of the complete air washerapparatus has been included. Here it will be seen that a plurality ofrotating eliminator assemblies 58, each of generally the sameconstruction as the eliminator assembly shown in FIGS. 1-10 are mountedon a through shaft 59 and are arranged for independent rotation by meansof separate electrical motors 61 mounted on the outside of the casing d.These motors are coupled to their respective rotating eliminatorassemblies by suitable drive means such as a chain and sprocket drive,one driving sprocket 62 being secured on the motor shaft and the other,driven sprocket 63 being secured on one of the hubs 64 of the associatedrotary eliminator assembly 58, the sprocket chain 65 between the twosprockets being passed through an aperture established in the casingpart 10d which encloses the eliminator assemblies.

As previously indicated, the motors 61 may be driven in the samedirections and at different speeds, or the motors of adjacent eliminatorassemblies maybe driven in opposite directions and also at the same ordifferent speeds.

It has also been found advantageous to. operate a plurality of cascadedeliminator assemblies in the same direction but at different speeds.Thus, for example, considering a group of three adjacent assemblies, thetwo outer assemblies of the group can be rotated at the same speed, forexample, 130 r.p.m., while the intermediate assembly can be rotated inthe same direction but at a slower speed, for example, 34 r.p.m.

It is also possible to arrange the cascaded eliminator assemblies so asto maintain one assembly stationary while other assemblies adjacentthereto are rotated. This serves to re-direct the air stream betweenadjacent assemblies to bring about the most effective air entrance angleinto the downstream eliminator assembly for the purpose of eliminatingthe entrained water particles.

The several eliminator assemblies 58 may have the same number ofeliminator blades 37 or each assembly may have a different number ofblades. Preferably the assembly 58 With the fewest blades is locatedupstream of the eliminator while succeeding assemblies as counted in thedirection of air flow through the apparatus are provided with a greaternumber, e.g., progressively increasing numbers of blades. Used in thismanner, the upstream assemblies 58 which receive the maximum amount ofentrained water and dirt being washed from the air have less totalsurface area to contaminate and are more easily cleaned when cleaningbecomes necessary, and the assemblies further downstream with moreblades run in a much cleaner atmosphere and hence are capable ofremoving smaller water particles from the air. This latter function ispossible since eliminating efficiency is, in part, improved when moreblades are added to the hub, or when the eliminator blades are revolvedat a higher rotational speed.

It has been explained that the eliminator may be positively driven inrotation by a motor or that it may be caused' to rotate by means of awindmill that can be automatically controlled so as to control therotational speed of the eliminator. FIGS. and 16 illustrate anarrangement wherein the drive shaft 31 of the eliminator assembly 30 isdriven by a windmill secured to the shaft, the blades of the windmillhaving a variable pitch controlled by a governor whose setting is madevariable in accordance with the particular parameter involved such thatthe variable pitch windmill drive unit is secured to the drive shaft 31directly behind the eliminator blade assembly 36 and downstream from thebearing support for the rear part of the eliminator drive shaft 31. Inparticular, it will be seen that the entire windmill assembly is builtinside of and around a casing 66 which is keyed to eliminator shaft 31by key 67. In this manner the eliminator shaft 31 is caused to rotate inunison with casing 66 which forms the bearing supports for four windmillblades 68, 69. These four windmill blades are disposed 90 apart andextend from their hub section which is casing 66 and are aerodynamicallycorrect airfoil sections. Blade shaft 71 extends through and issupported in hearings in casing 66 at points 72, 73 so that each bladeis rigidly supported but is free to rotate about the center line ofshaft 71. Each of the blade shafts 71 has a pinion gear 74 firmlysecured thereto so that it must rotate with its respective shaft. A facegear 75 is supported in-bearings on eliminator shaft 31 and is locatedon shaft 31 by a collar 76 and the hub section of casing 66. In thismanner face gear 75 is maintained in operating contact with each pinion74 and the two gears must always rotate together. Face gear 75 has twoaxles 77, 78 fixed to and projecting perpendicularly from its face sothat control gears 79, 80 can be rotatably mounted on face gear 75.Control gears 79, 80 are mounted at the proper radius from the centerline of shaft 31 so that they engage to drive or be driven by a gear 81which is supported in hearings on shaft 31 but retained in a fixedposition on shaft 31 by collar 76. A drive stud 82 is rigidly attachedto gear 81 and the two are made to rotate together. An air operatedmotor of the cylinderpiston type has its piston 83 and piston rod 84flexibly mounted to stud 62 on one end and its cylinder 85 flexiblymounted on casing 66 by a clevis pin 86. Connected in this manner, theair cylinder 85 retains gear 81 in a fixed position so that it mustrotate with shaft 31.

Control gear '79 has rigidly fixed to its face a fiyball control arm 87and a flyball 88. Similarly, control gear 80 has rigidly fixed to itsface a fiyball control arm 89 and a fiyball 919. It will be seen fromFIG. 16 that the tWo control arms 87 and 89 are urged inwardly bysprings 91 and 92, respectively. Control arm 87 is provided with a stop93 and control arm 89 is similarly provided with a stop 94 so that theycannot come so far in that they touch the drive stud 82 or change thepitch of the windmill blades beyond a predetermined point.

The air operated motor is of the spring-return type so that the airpressure exerted against piston 83 achieves a force balance relationshipwhich will fix the displacement of piston rod 84 with relation tovariations in input control pressure, the latter being varied as afunction of the change in the particular parameter utilized to controlthe speed of the eliminator. As shown in FIG. 15, the control airpressure is directed to the pitch changing mechanism through a tube 95,then through a rotary union 96 and finally through another tube 97 whichleads to the interior of motor cylinder 85. In this manner, the airmotor maintains gear 81 ina fixed position relative to casing 66 as longas piston rod 84 does not move. However, it is seen that an increase inair pressure within the cylinder 85 will cause gear 81 to rotaterelative to shaft 31 through a certain number of degrees as determinedby the stroke of piston rod 84 and the radius of the center line ofdrive stud 82 relative to shaft 31. When gear 81 is rotated relative toshaft 31, it can perform one of two functions or a combination of both.It can either rotate control gears 79, 80 about their individual axes orit can rotate the face gear 75 relative to shaft 31. This resettingtendency is described hereinafter.

Since the entire casing 66 and the mechanism therein is revolved atshaft speed, fiyball 88 and 90 are acted upon by centrifugal force of amagnitude determined by the rotational speed of shaft 31. As centrifugalforce on the unit is built up by bringing casing 66 up to apredetermined speed, flyballs 88 and 90 along with their respectivecontrol arms 87 and 89 move outwardly away from shaft 31 carrying withthem in a rotative manner, control gears 79, 86 to which they areindividually attached. The fiyball assemblies will move outwardly untiltheir force is balanced off by the inward force being exerted by thecombination of springs 91 and 92. This operation will arrest anyadditional movement caused by centrifugal force as long as shaft 31maintains a constant rotational speed. When the entire unit is at rest,the flyballs are positioned as shown in FIG. 16 and all of the windmillblades 68, 69 are positioned relative to the air stream through theeliminator at their maximum angle of attack. That is to say, they are ina position relative to the air stream which will exert the greatestamount of torque on shaft 31 as the air moves by the blades at highvelocity.

As the eliminator assembly 30 begins to come up to its operating speed,flyballs 38 and 90 rotate control gears 79 and 8t? against the immovablegear 31 so that their axles 77, 78 cause face gear 75 to rotate relativeto shaft 31 and in turn rotate the pinions 74 meshed with gear 75 so asto begin to feather the four windmill blades in unison. When the desiredbasic operating speed of the eliminator assembly 30 is reached, thewindmill blades will have feathered to a position such that theircombined lift exerts a torque on shaft 31 which is exactly equal andopposite to the air load and friction of the eliminator assembly whichis being driven by rotation of shaft 31. Any increase in speed causedby, for example, a slight increase in the air velocity through thewasher will cause the flyballs 88, 90 to move further away from shaft 31and further feather the Windmill blades so as to maintain a constantspeed. Likewise, any decrease in eliminator speed from the designatedcondition will cause the fiyballs to move inwardly toward shaft 31because of centrifugal force, and the windmill blades will increase inpitch until the increasing coefficient of lift will exert the requiredamount of torque to bring the rotating eliminator assembly back to theset basic speed.

Obviously, the final speed of the eliminator assembly in any one fixedposition will be determined by the pitch of the air foiled shaped bladeswhen the unit is at rest, such as depicted in FIG. 16. Therefore, achange in the final maximum speed can easily be accomplished by rotationof gear 81 relative to shaft 31 by the air pressure actuated piston 83since it effectively changes the pitch of all windmill blades when theyare at rest. This operation can be performed during high speed rotationof the eliminator assembly 3% since the pressure air admitted intocylinder 85, and which varies in pressure as a function of thecontrolling parameter, enters the speed control unit through the rotaryunion 96.

It will thus be seen from FIGS. 15 and 16, that the adjustable fiyballgovernor which has been described serves to continuously re-adjust thewindmill blades 68, 69 to maintain a selected basic operating speed forthe eliminator assembly 30, and that this basic speed can also beautomatically adjusted up or down in accordance with variation in adesired parameter such as the condition of the air in a textile roomwhich is supplied with air from the outlet of the eliminator assembly.

Since a rotating eliminator with substantially planar blades shouldoperate on a proportional basi relative to water droplet size, i.e. thelarge droplets should come out on the upstream side of the eliminatorand the droplet size moving through the eliminator channel shouldcontinuously diminish until one either strips all of the liquid out oruntil, at a rotational speed which would be under that for completeelimination, a very fine droplet mist would issue from the eliminator.In this manner one is enabled to control in a very accurate manner theamount of boost or entrainment leaving the eliminator and thus obtain acompletely controllable wet duct system by virtue of changing therotational speed of the eliminator. Obviously, this speed control of theeliminator can also be obtained by driving the eliminator from avariable speed electric motor as in FIG. 1 which could be controlled asto speed by conditions in the room receiving air from the eliminator.

During operation of the eliminator, it is possible that some dirt, lint,and other particulate material may become stuck on the surfaces of theblades, and in the gaps between adjacent blades thus interfering withproper operation of the apparatus and increasing the static pressurelosses. While dirt accumulation and clogging are not serious factors inthe improved eliminator structure due to the fact that the blades areessentially planar throughout their area of contact with the air beingpassed through the eliminator, some dirt and clogging may occur andhence, it is advantageous if arangements are made for convenientlycleaning off the blades. FIG. 17 illustrates one suitable arrangementwherein it will be seen that a row of nozzles 101 project from a headerpipe 102 inserted radially into the axial gap between the ends ofadjacent eliminator assemblies 58 in such manner as to direct streams ofwater under considerable pressure longitudinally upstream and downstreamthrough the assemblies to Wash out any particulate matter which may havebecome lodged between adjacent blades or on the blade surfacesthemselves. It will be noted that each row of nozzles 101 extends fromthe inner to the outer edges of the blades thus assuring adequateclean-off of the entire surface area of the blades.

In addition to or in lieu of the radial row of flooding nozzles 101 wecan provide one or more other flooding nozzles 191 located on that partof header 102 which extends longitudinally of and just inside the casingwall Gd. The one or more nozzles 101' are so oriented as to direct theirdischarge either in a truly radial direction inwardly toward the hub, orat a-slight angle to a radial line so as to also provide a turbineeffect which can be used to effect a comparatively slow rotation of theeliminator assembly during cleaning. Motors 61 can also be operated at aslow speed for cleaning.

When it is desired to clean out the bladed eliminator assembly orassemblies if there be a plurality of them arranged in cascade as shownin FIG. 17, the apparatus is shut down which includes cutting off thewater nozzles 24, 25, cutting off the fan 12 and cutting off the motoror motors 46, 61 which drive the bladed eliminator assemblies inrotation.

The flooding nozzles 101 are then turned on to operate for the desiredtime and can then be turned off and the eliminator assembly placed backinto normal operation.

If desired, the cleaning sequence can be programmed to operate on agiven cycle with the aid of a timer motor and the necessary switchingdevices which will switch the various operating components on and off atthe proper times and in the correct sequence. Thus, for example, thecleaning cycle can be set up to provide the following sequence ofoperations:

(1) Cut off water to air washer nozzles 24, 25 by cutting off pump 18.

(2) Cut off fan 12 by de-energizing its electric motor drive.

(3) Cut on flooding nozzles 101 by energizing a solenoid control valvein header pipe 192.

(4) Cut off eliminator drive by de-energizing its electric motor drive46 or 61.

Since the eliminator assembly 30, or assemblies 58 have considerablemomentum due to their relatively great mass, the desired back floodingof the surfaces of the eliminator plates to clean them. can then takeplace while the eliminator assembly is running down to stand-still fromits normal rotating speed following cut-off. After the eliminatorassembly or assemblies have reached a standstill condition, their motorscan then be re-energized to thus restart them, gradually bringing themback up to their normal rotating speed, the flooding nozzles 101 canthen be cut oif, this being followed by cutting on fan 12 and restartingpump 18 to re-start the flow of air washer water from nozzles 24, 25.This entire cycle can be made to take place in the desired overall timewhich can be of the order of 30 seconds, and can be repeated at thedesired intervals in an automatic manner by means of the timermechanism.

If the back-flooding feature is applied to. the single eliminatorassembly structure as shown in FIG. 1, the nozzles 101 would be placedat the downstream, or right hand end of the assembly 30 and thesenozzles would be so oriented as to direct streams of water back alongthe surfaces of the blades 37 towards the left or entrance end of theassembly.

In the embodiments of the invention which have been described, theblades 37 of the eliminator assembly, or assemblies if there be two ormore such assemblies arranged in cascade as shown in FIG. 18, arearranged in planes parallel to the rotational axis of the assembly. Ifdesired, the blades may be arranged in planes disposed at an acute angleto the axis of rotation. Such a modified construction is illustrated inFIG. 19, it being noted that for a cascaded arrangement the blades 37 ofone eliminator assembly are angled in one direction away from the axiswhile the blades 37" of an adjacent eliminator assembly are angled inthe opposite direction with respect to the axis thus giving aherringbone effect. The oblique angled setting of the blades of theeliminator can also be applied to a construction in which there is but asingle rotatable assembly.

In conclusion, it will be understood that while preferred embodiments ofthe invention have been disclosed and illustrated, various changes maybe made therein in the specific construction and arrangement ofcomponent parts without, however, departing from the spirit and scope ofthe invention as defined in the appended claims.

We claim:

1. In a combined air washer and eliminator, the combination comprising acasing having an air inlet at one end and an air outlet at the, otherend, motor driven iian means for moving the air stream to be treatedthrough said casing between said inlet and outlet, a washer chamberlocated within said casing and including water spray means for effectingcontact with the air, an eliminator chamber located within said casingon the downstream side of said Washer chamber, a rotatable shaft mountedbladed eliminator assembly located within said eliminator chamber, saideliminator assembly comprising a plunality of radially extending bladeswhich are essentially planar between the air inlet and outlet edgesthereof for producing a centrifugally induced helical outward flow pathof liquid droplets separated out of the air st-r'eam, a windmill mountedon the shaft which mounts said eliminator assembly, said windmill beingdriven by the air stream passed through said washer and eliminatorchamber and being provided with blades having adjustable pitch, andadjustable speed governor means on said windmill t or changing the pitchof said windmill blades, said speed governor means being responsive to achange in a parameter related to use of the air dischanged from saideliminator assembly for efiecting a corresponding adjustment in thesetting of said speed governor means thereby to efiect a correspondingchange in the speed of said windmill and eliminator assembly and hence acorresponding change in the amount of moisture removed from said airstream.

2. In a combined air washer and eliminator, the combination comprising a:casing having an air inlet at one end and an air outlet at the otherend, fan means for moving air to be treated through said casing betweensaid inlet and outlet, a washer chamber located within said casingincluding spray means for effecting contact with the air, an eliminatorchamber located within said casing on the downstream side of said Washerchamber, a group of three coaaxially mounted rotatable eliminatorsections arranged in cascaded relation within said eliminator chamber,each said eliminator section comprising a plurality of radiallyextending blades which are essentially planar between the inlet andoutlet ends of the section for producing a centrifugally induced helicaloutward flow path of liquid droplets separated out of the air stream,and means for rotating all three eliminator sections of the group in thesame direction, said rotating means including means for rotating the twoouter eliminator sections of said group at the same speed, and means forrotating the intermediate eliminator section at a speed less than halfthat of said outer eliminator sections.

3. A combined air washer and eliminator as defined in claim 2 whereinthe rotary speed of the intermediate eliminator section is of the orderof one-fourth that of the two outer eliminator sections.

4. A combined air washer and eliminator as defined in claim 2 whereinsaid eliminator sections are provided with an increasing number ofblades as relatedto the direction of air flow through the eliminatorchamber.

References Cited by the Examiner UNITED STATES PATENTS 926,647 6/ 1909Flossel 261- 991,157 5/1911 Kestner 5591 1,112,381 9/1914 Patitz 261-891,292,561 1/1919 Baldwin 55401 1,480,775 1/1924 Marien 55-407 1,511,83410/1924 Marien 55401 1,864,803 6/1932 Clark 170 1,898,807 2/1933 Barnes55-91 2,007,734 7/1935 Wergifosse 261--90 2,509,173 5/1950 Schreier etal 55404 X 2,922,489 1/ 1960 Hollingsworth 55217 2,932,360 4/1960Hungate 55257 X 2,953,355 9/1960 Hungate 55-257 X 2,954,841 10/1960Reistle 55404 X 2,962,116 11/1960 Hayes et al 55404 X 2,975,861 3/1961Hay'es 55408 X 3,058,720 10/ 1962 Hart et a1. 55408 X 3,073,095 1/1963Hungate 55257 3,073,096 1/1963 Hayes 55257 FOREIGN PATENTS 7,997 6/ 1902Austria.

561,554 10/1957 Belgium. 1,009,096 2/ 1952 France.

904,260 2/ 1954 Germany.

284,312 5/ 1928 Great Britain.

332,859 7/1930 Great Britain.

732,622 6/ 1955 Great Britain.

ROBERT F. BURNETT, Primary Examiner.

1. IN A COMBINED AIR WASHER AND ELIMINATOR, THE COMBINATION COMPRISING ACASING HAVING AN AIR INLET AT ONE END AND AN AIR OUTLET AT THE OTHEREND, MOTOR DRIVEN FAN MEANS FOR MOVING THE AIR STREAM TO BE TREATEDTHROUGH SAID CASING BETWEEN SAID INLET AND OUTLET, A WASHER CHAMBERLOCATED WITHIN SAID CASING AND INCLUDING WATER SPRAY MEAND FOR EFFECTINGCONSTACT WITH THE AIR, AN ELIMINATOR CHAMBER LOCATED WITHIN SAID CASINGON THE DOWNSTREAM SIDE OF SAID WASHER CHAMBER, A ROTATABLE SHAFT MOUNTEDBLADED ELIMINATOR ASSEMBLY LOCATED WITHIN SAID ELIMINATOR CHAMBER, SAIDELIMINATOR ASSEMBLY COMPRISING A PLURALITY OF RADIALLY EXTENDING BLADESWHICH ARE ESSENTIALLY PLANAR BETWEEN THE AIR INLET AND OULET EDGESTHEROF FOR PRODUCING A CENTRIFUGALLY INDUCED HELICAL OUTWARD FLOW PATHOF LIQUID DROPLETS SEPARATED OUT OF THE AIR STREAM, A WINDMILL MOUNTEDON THE SHAFT WHICH MOUNTS SAID ELIMINATOR ASSEMBLY, SAID WINDMILL BEINGDRIVEN BY THE AIR STREAM PASSED THROUGH SAID WASHER AND ELIMINATORCHAMBER AND BEING PROVIDED WITH BLADES HAVING ADJUSTABLE PITCH, ANDADJUSTABLE SPEED GOVERNOR MEANS ON SAID WINDMILL FOR CHANGING THE PITCHOF SAID WINDMILL BLADES, SAID SPEED GOVERNOR MEANS BEING RESPONSIVE TO ACHANGE IN A PARAMETER RELATED TO USE OF THE AIR DISCHARGED FROM SAIDELIMINATOR ASSEMBLY FOR EFFECTING A CORRESPONDING ADJUSTMENT IN THESETTING OF SAID SPEED GOVERNOR MEANS THEREBY TO EFFECT A CORRESPONDINGCHANGE IN THE SPEED OF SAID WINDMILL AND ELIMINATOR ASSEMBLY AND HENCE ACORRESPONDING CHANGE IN THE AMOUNT OF MOISTURE REMOVED FROM SAID AIRSTREAM.